Actuating means for a multispeed cycle hub

Abstract

An actuating mechanism for a multispeed cycle hub comprises a housing adapted to be attached to an end of a hub shaft. A first cam, a second cam, and a pinion having engaging teeth are received in the housing for conjoint rotation. An elongated rack element is mounted for movement along an axis in the housing and is adapted to be coupled to a speed-selection device by a force-transmission member and includes a row of teeth in driving engagement with the engaging teeth of the pinion. A first pivot lever is pivotally mounted in the housing in constant contact with the first cam so as to follow a pivoting motion defined by the shape of the first cam and engages one of two speedchange elements, which are coupled to the transmission in the hub, so as to move the first speed change element upon pivotal movement in response to rotation of the first cam. A second pivot lever is pivotally mounted in the housing in constant contact with the second cam so as to follow a pivoting motion defined by the shape of the second cam and engages the other of the two speed change elements so as to move the second speed change element upon pivotal movement in response to rotational movement of the second cam.

It is claimed: 
     
       1. An actuating mechanism for a multispeed cycle hub having a hub axle with two hub ends defining an axis of rotation, a hub sleeve rotatably mounted on the hub axle, a transmission shiftable among several speeds received in the hub sleeve, at least one drive gear in driving connection with an input element of the transmission, at least one output element of the transmission in driving connection with the hub sleeve, a bore extending axially through the hub axle, two elongated compressionally rigid speed change elements received in the bore of the hub axle parallel to the axis of rotation and having inner ends coupled to the transmission for shifting between speeds and outer ends extending into a region proximate to one of the two hub ends, the actuating mechanism comprising: a housing adapted to be attached to the one hub end,   a first cam, a second cam, and a pinion having engaging teeth, the first cam, second cam and pinion being connected to each other for conjoint rotation and forming a rotatable unit mounted in the housing for rotation about an axis,   an elongated rack element having a longitudinal axis and mounted in the housing for movement parallel to the longitudinal axis, the rack element being adapted to be coupled to a speed-selection device by a force-transmission member and including a row of teeth in driving engagement with the engaging teeth of the pinion,   a first pivot lever pivotably mounted in the housing in constant contact with the first cam so as to follow a pivoting motion defined by the shape of the first cam and engaging one of the two speed change elements so as to move the first speed change element upon pivotal movement in response to rotation of the first cam, and   a second pivot lever pivotally mounted in the housing in constant contact with the second cam so as to follow a pivoting motion defined by the shape of the second cam and engaging the other of the two speed change elements so as to move the second speed change element upon pivotal movement in response to rotational movement of the second cam.   
     
     
       2. An actuating mechanism according to claim 1, and further comprising arrest means received in the housing for releasably establishing a plurality of arrest settings of the rotatable unit, each arrest setting corresponding to a speed of the shiftable transmission. 
     
     
       3. An actuating mechanism according to claim 2, wherein the arrest means comprises an arrest projection element mounted in the housing for movement between an engagement position and a disengagement position and biased into the engagement position by a spring element and an undulating arrest surface on the rack element, said arrest surface having a plurality of arrest notches aligned in succession in the direction of the longitudinal axis, each notch being associated with a speed of the transmission. 
     
     
       4. An actuating mechanism according to claim 1, wherein the housing has two housing parts connected to each other and forming an essentially closed housing. 
     
     
       5. An actuating mechanism according to claim 4, wherein at least one of the housing parts is provided with support means for supporting at least one of the rotatable unit, the first pivot lever, the second pivot lever, and the rack element. 
     
     
       6. An actuating mechanism according to claim 4, wherein each of the two housing parts constitutes a half-housing. 
     
     
       7. An actuating mechanism according to claim 1, wherein the first cam, the second cam and the pinion are carried by a common shaft. 
     
     
       8. An actuating mechanism according to claim 1, wherein the rack element is adapted to be connected to the force-transmission member by a fastening screw threaded into the rack element and the rack element is provided with an aperture extending parallel to the longitudinal axis and extending substantially throughout the length of the rack element, the aperture being adapted to receive a free end segment of the force-transmission member adjacent to the fastening screw. 
     
     
       9. An actuating mechanism according to claim 8, wherein the housing has a tool access opening in the region of the rack element and a removable closure element is installed in the access opening, whereby adjustment of the fastening position of the rack element on the force-transmission member is afforded by removing the closure element and inserting a tool through the access opening to release and retighten the fastening screw. 
     
     
       10. An actuating mechanism according to claim 1, and further comprising restoring spring means in the housing for biasing the rotatable unit so as to assist in establishing at least one but less than all of the speeds of the transmission. 
     
     
       11. An actuating mechanism according to claim 10, wherein the restoring spring means includes a spring received in the housing, the spring having one end engaging the housing and the other end engaging the rack element when the rack element is in positions establishing said at least one but less than all of the speeds of the transmission. 
     
     
       12. An actuating mechanism according to claim 11, wherein said other end of the spring engages a holding element having an aperture, and the rack element has a projection movable through the aperture to engage the other end of the spring. 
     
     
       13. An actuating mechanism according to claim 12, wherein when the force-transmission member is pulled out of the housing to execute a speed change of the transmission, the spring of the restoring spring means is increasingly compressed. 
     
     
       14. An actuating mechanism according to claim 3 wherein the rack element is received in a slideway in the housing on a side of the rack element remote from the arrest projection element of the arrest means. 
     
     
       15. An actuating mechanism according to claim 1, wherein the rack element has a head, the head receives a fastening screw for the force transmission member, and the head is guided in a guide formed in the housing. 
     
     
       16. An actuating mechanism according to claim 1, wherein the first pivot lever and the second pivot lever are received for pivotable movement on a common pivot bearing pin in the housing. 
     
     
       17. An actuating mechanism according to claim 16, wherein the first pivot lever and the second pivot lever are of two-arm configuration, each having a cam following end and an actuating end acting upon the respective speed-change elements. 
     
     
       18. An actuating mechanism according to claim 1, wherein the two speed-change elements are compression rods that extend parallel to the axis of rotation through the bore of the hub axle and are disposed side by side laterally of the axis of rotation. 
     
     
       19. An actuating mechanism according to claim 18, wherein the compression rods are of approximately semicircular cross section and are disposed with the diameters of the semicircles facing each other. 
     
     
       20. An actuating mechanism according to claim 19, wherein the two compression rods are in contact with each other by way of projections running parallel to the axis of rotation. 
     
     
       21. An actuating mechanism according to claim 20, wherein one of the two compression rods has a projection in the region of the vertex formed between the diameter and the circumference of the cross-sectional semicircle, and the other compression rod has a projection in the region of the vertex between the diameter and the circumference of the cross-sectional semicircle diametrically opposed to the projection on said one compression rod. 
     
     
       22. An actuating mechanism according to claim 18, wherein one of the two compression rods is longer than the other compression rod and extends farther into the hub axle than the other compression rod, and in that the longer compression rod is secured against twisting inside of the hub axle. 
     
     
       23. A multispeed cycle shift apparatus comprising a multispeed cycle hub having said actuating mechanism according to claim 1 speed-selection means, and a force-transmission member connecting the actuating mechanism to the speed-selection means.